1. Technical Field
The disclosure relates generally to integrated circuit (IC) chip fabrication, and more particularly, to ionizing radiation blocking in an IC chip to reduce soft errors.
2. Background Art
Soft errors caused by ionizing radiation including, for example, alpha particles, beta radiation, cosmic rays, high-frequency electromagnetic radiation, or other types of radiation capable of producing a change in electrical state, are an increasingly large problem for integrated circuit (IC) chip fabricators. In particular, the continual miniaturization of IC chip circuitry and increased performance requirements has caused fabricators to focus more attentively to soft error rates (SER) caused by ionizing radiation, which drain performance. One approach to address this issue is to use external radiation shields about an IC chip. Ionizing radiation, however, can enter an IC chip from a number of sources such as the package to which an IC chip is attached, e.g., through the interconnecting solder. As a result, external shields are not always effective. Another approach is to use special circuitry within an IC chip to prevent the ionizing radiation from altering electrical states. However, special circuitry spends resources, e.g., space, power, etc., that may be better used for the overall IC chip function.